WBB GP-9 Gear Compatibility w/PW Lionel GP-9

Started by Len, December 23, 2019, 07:38:53 AM

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Len

Five of the six WBB GP-9's I use on the display layout I maintain are now down due to worn out brass worm gears. The replacement 4-Wheel Geared Trucks, 203-GEARED-C, have been out of stock for quite a while now, so I'm looking at alternatives.

Does anyone know if the 2328-80 worm gear from Post War Lionel GP-9's will fit the gear shaft of the WBB GP-9's?

Part of me is thinking of ordering a couple and giving it a try, but if the hole in the PW gear is larger than the WBB shaft I don't want to waste time pulling the WBB truck apart.

Len
If at first you don't succeed, throw it in the spare parts box.

trainyardjp

JP of Acton MA, USA writes,

If there is a concern regarding worm gear hole size differences between the Post War unit and the Williams unit, you could try using brass (or steel) tubing to reduce the larger hole size, down to the size you desire. Usually, hardware stores or hobby shops would sell these tubes, and they would have to be super glued together, one inside the other.
Hope this helps.
-JP
-JP

Len

My concern is these locos operate on push-button activated timers, so they're subject to sudden starts and stops. I'm afraid the torque involved would eventually loosen the glued together tubing. Especially with grease in direct contact with any glue involved. So I'd prefer gears that are good 'press fits' for the shafts involved.

I was just hoping someone would know if the Williams/Williams by Bachmann GP-9 worm gear shaft is the same size as the Post War Lionel GP-9.

Len
If at first you don't succeed, throw it in the spare parts box.

trainyardjp

JP of Acton MA, USA writes,

Ah. Ok.
Maybe 'The Bachmann', '3 Rail', or 'Yardmaster' might know.

As for your push-button operated layout, perhaps if you reduced the voltage a bit, then you might not wear out the worm gears, as often, vs. operating with a higher voltage.
-JP
-JP

Len

There's a limit to how low I can set the voltage and still get consistent starts when a button is pushed. As well as get a train up and down the grades of a particular loop on the layout. The real problem with gear wear is, even with the buttons and timers, the trains are running the better part of 10 hours a day, 6 days a week.

Over time, that much running generates enough heat to soften the brass worm gear some. Which is one of the reasons we try and stick with Williams/Williams by Bachmann locomotives. For whatever reason, I suspect differences in the brass alloys used, other brands of locos wear out their gears even faster than the Williams locos.

But the replacement 4-wheel geared trucks being out of stock for so long has gotten things to the point I'm searching for alternatives short of buying completely new locos.

Len
If at first you don't succeed, throw it in the spare parts box.

671

#5
Merry Christmas Len,

        671 here. Reading your posts indicates two challenges that you are facing.

1.   Driven gear replacement for your GP 9's. I would suggest that you take a gear that is in like new condition to a Machine Shop. They should be able to duplicate that gear in what ever metal that they suggest. ( Silicone bronze? ) Have them make several. Probably the more the cheaper each will cost.

2    Driven gear wear and failure. Sudden starts of you locos due to push button or timer start. The heavy "in rush" of current is putting strain into the drive train of the locos. This sudden inrush overloads the gearing causing failure.
     The answer to this challenge is an electrical devise called a Thermistor.  There are two basic types:

        A PTC Thermister and a NTC  Thermistor....You NEED a NTC thermistor

     How the NTC Thermister works. When wired in series with a load ( Motor Circuit ) in your case. When power is not applied to the circuit, the resister is cool, the resistance rating at this point is high (difficulty of current passing through the Thermistor). When power is applied (on), the Thermistor quickly heats up. The resistance through the resister becomes almost zero. At this point it allows current to flow energizing the motor circuit. Your result will be as if you were "Hand Throttling" the loco. The loco will receive a gradual inrush of current. This will happen all within one to two seconds. No strain will be suddenly applied to the gear set.
      Sometimes these resisters are called "In Rush" resisters.
      You will need to check with an electronic component supply house to get the correctly rated thermistor.  You need to stay within the parameters of your voltage,amperage, ohms.  The voltage will need to handle the transformer out put say something over 25-30 volts. Amperage is probably over a range of 5-10 amps. The ohms you will need to see what is available and make a selection from the supplier. Just remember... the Higher the ohms the greater the starting resistance to current flow, the longer it will take for the motor circuit to go to full power. You may want to purchase several different ratings to 'see' what works best for you.

                                           Hope this helps...671

671

Len,

      671 here again. This is one other tip will make your dual motor locos perform better for you.

      Wire the motors in series. They come from the factory wired in parallel. Parallel causes them to be very sensitive to voltage variations. I have done this to many of my dual motor units. They perform so much better at slower speeds. They go up inclines better and the sound card activates more consistently, due to the higher track voltage.

      There are posts on this site that give instruction as to how to change the wiring. Take a look at them. The wiring change is easy.

                                            Keep Them Smokin'...671

Len

671,

Thanks for the tip about the thermistors. Once I get some replacement trucks, or find a good replacement gear, I'll give it a try.

And the first thing I do with any two motor loco before it goes on the display layout is wire the motors in series. Learned about that one some time back.

Len
If at first you don't succeed, throw it in the spare parts box.

671

Hi Len,

       671 here. More info for you...

The inrush current limiter CL 150 is rated at a constant 4.7 amps.  An online site, Newark, has them for less than a dollar each.

This would be a choice that I would try.

                                             Hope this helps...671

Len

Thanks for the info. Since no one seems to know, I ordered a couple of worm gears to find out if they'll fit or not.

Len
If at first you don't succeed, throw it in the spare parts box.